Thanks for the suggestions. I guess I will look into a coating. I will:
1.try to break off or remove the brittle and pointed pieces at the edge or around cracks
2. scrub off the moss like stuff that was trying to grow in some places and any other dirt I can get off
3. remove the vents, AC, antenae, and plumbing vent caps (all vents and caps need replacing anyway)
4. recoat with the coating material
5. re-attach of the parts removed and use new sealing mastic
6. seal screw holes and edgest with self leveling sealant
Then I think I should be good to go (I think). Removing and re-sealing the roof penetrations will really make me have peace of mind.
Is removing the AC to re-seal going to be difficult?